As a highly efficient bonding material, hot melt adhesive film is simple to use but very particular. Depending on different application scenarios and equipment requirements, the method of using hot melt adhesive film is also different. Then how to use hot melt adhesive film? Simply put, when using hot melt adhesive film, it needs to be heated at high temperature to melt the adhesive film. The melted liquid adhesive can infiltrate the surface of the adherend. At the same time, a certain pressure is applied. After the hot melt adhesive film is cooled and hardened again, the adhesive itself forms a cohesive force, which also generates bonding strength and bonds the adherends together. The use of hot melt adhesive film is mainly divided into large-area composite and small-area bonding.
Basic Principle of Hot melt Adhesive Film
The use of hot melt adhesive film is inseparable from the effects of high temperature and pressure. First, the hot melt adhesive film begins to melt by high temperature heating to form a liquid colloid. At this time, the liquid colloid can effectively infiltrate the surface of the adhered to ensure the firmness of the bonding. During the bonding process, in addition to controlling the temperature, a certain amount of pressure must be applied to ensure the close bonding between the materials. After the hot melt adhesive film cools and re-solidifies, it forms its own cohesive force, thereby achieving bonding strength and firmly combining the materials.
Large Area of Clothing and Other Fabrics
In the textile and clothing industry, hot melt adhesive films are particularly widely used. For large-area lamination, laminating machine equipment is usually used. This type of equipment is often used for laminating textiles, clothing fabrics, leather products, foaming materials and other coils.
Generally, the laminating factory uses a large roller laminating machine. As long as the previous glue tank is replaced with a bearing that can carry the hot melt adhesive film roll material, it can be used normally. When using it, adjust the temperature of the laminating roller to the hot melt adhesive film process temperature, sandwich a layer of hot melt adhesive film between the materials to be laminated, and enter the laminating roller together. The three layers of material follow the roller to rotate a circle and come out to be laminated together.
For the above categories of materials, if the format is small, the lining machine is often used for laminating.
Composite Application of Sheet and Metal Plate
Hot melt adhesive film is not only suitable for the lamination of flexible coils, but also widely used in the bonding of sheet and metal plate. Unlike flexible materials, the bonding of plates usually requires the use of a hot press. The following are the steps for using hot melt adhesive film in the composite of plates and metal plates:
Spread the hot melt adhesive film between the two layers of plates to be bonded, and then put them into the hot press together, take them out after a period of hot pressing, and cool them during the waiting period. It is worth mentioning that for the bonding of plates like this, the material often produces thermal stress after hot pressing, so there is often stress shrinkage during the cooling process, which causes the plate to deform to a certain extent, and the hot melt adhesive film must wait until it is completely cooled and hardened before the bonding strength can reach the best, so debonding often occurs during the cooling process due to deformation. Therefore, when using hot melt adhesive film to bond such plates, it is generally necessary to go through a cold pressing process. After the hot melt adhesive film is completely cooled, the pressure is removed, and the bonding strength can reach the best.
Application of Small Area Bonding
In addition to large-area composites, hot melt adhesive films are also widely used in the field of small-area bonding. For example, in the production of seamless clothing, hot melt adhesive films are used for bonding between fabrics, and seamless splicing machines are usually used at this time. The equipment uses high-frequency hot melt technology to quickly heat and bond fabrics to achieve efficient and seamless bonding.
In addition to the above large-area bonding, there are many cases of small-area bonding, such as the hot melt adhesive film and hot melt adhesive web used in the production process of seamless clothing, which is often completed using a seamless splicing machine. This machine uses high-frequency hot melt technology as the principle, which can quickly heat the splicing parts and achieve rapid bonding between fabrics. In addition, the bonding of small-area can also be done manually with using more primitive methods such as electric irons, flat-plate presses, heat sealers, hot air guns and other equipment.
